PURPOSE: To decrease the error of temperature measurement due to the background light, by setting an angle of the material to be measured facing to a radiation thermometer at a specific angle determined by an optical constant of the surface of the material to be measured and also and providing a polarized light apparatus on a photodetecting part.
CONSTITUTION: A radiation thermometer 17 is set so as to face to a slab 3 the temperature of which is measured at an angle θB. θB is the angle of being a reflection factor of polarized light component in an incident face minimum. A polarized light apparatus 20 intercepting the polarized light component in the direction crossing at right angles to the incident face, is provided to a detection part 21. The apparatus 20 is composed of a relfecting board 24 having a high transmittance of infrared rays such as CaF2 and a light shielding board 28 and an input light 23 is made incident to the part 21 by reflecting with the board 24, the board 24 is set up so as to cross at right angles to the incident face for the slab 3 and because of setting up an incident angle 26 to the board 24 at Brewster's angle, the polarized light component in the incident face for the board 24 is not included in a reflected light 25 and a transmitted light 27 is not varied by the board 28. Hereby, the error of temperature measurement by the background light is lessened.
| WO/2017/132053 | A VOLUMETRIC OCCUPANCY COUNTING SYSTEM |
| JPH10118034 | CLINICAL THERMOMETER |
| JP4052945 | Radiant thermometer with heated measurement tip |
SAEKI RIICHI
TAKEI TOSHIO
